Insomnia is a major mental health symptom related to depression, sleep loss, sleepiness, mistakes, accidents, irritability and anger. Major contributors to insomnia include periodic limb movements (PLM) in sleep and restless legs (RL). Night-to-night variability and expensive, inconvenient testing limits clinical and research work with these conditions. This project will develop technology needed to produce a self-contained, easily-used, ambulatory leg activity monitor (LAM) that will detect and record over several days the occurrence of characteristic periodic movements. The clinical monitor provides displays of PLM and RL rates while a research monitor records all relevant data at 10 Hz for 2+ days for PC analyses and display. These provide the first objective measurement of all naturally occurring RL and of all PLM over several nights permitting circadian analyses. Phase l showed feasibility of accurately capturing and correctly identifying all periodic movements. Phase 2 will serve to establish the LAM as a very user-friendly standard for diagnosis, severity assessment, screening and treatment evaluation and will provide for the first time an opportunity to analyze RL movements as they naturally occur. PROPOSED COMMERCIAL APPLICATION: The LAM will be marketed to all sleep disorders centers, all hospitals and medical centers with a movement disorders clinics, neurologists, psychiatrists, psychologists and family doctors. The marketing plan calls for establishing this technology as the standard for evaluating and screening for PLM and RL and with increased sales reducing the price sufficiently to develop good market penetration.